Diaphragm pump



A ril 29, 169 WAGNER 3,440,970

DIAPHRAGM PUMP Filed May 17, 1967 INVENTOR JOSEF WAGNER ATT-ORNEY United States Patent 3,440,970 DIAPHRAGM PUMP Josef Wagner, 7991 Friedrichshafen-Fischbach, Germany Filed May 17, 1967, Ser. No. 639,111 Int. Cl. F04b 43/08 US. Cl. 103-148 5 Claims ABSTRACT OF THE DISCLOSURE Background of the invention This invention relates to high pressure pumps adapted to deliver liquids including those of an abrasive or corrosive nature. In the past, pumps for such use which utilized a piston as the delivery means were subjected to excessive wear and damage, not only to the piston, but also the piston seals or rings. Such a disadvantage has been overcome by the well known diaphragm pump which contains a diaphragm moved by a pressurized fluid which in turn is acted upon by a reciprocating piston. However, should the diaphragm become damaged, and leak, portions of the pump mechanism are subject to damage, if not destruction, by any corrosive or abrasive material to be moved by the pump.

Equally as well known as the above described diaphragm pumps are hose pumps which contain mechan ical components, such as cams, etc., which convey the liquid in the hoses in successive pulsating surges. Where a hose pump design requires the hoses to enlarge under pressure, expandable materials must be selected for the hoses. However, where pressures are high (i.e. 2840 p.s.i.) the range of applications is limited and require elaborate safeguards to insure good sealing and trouble free service.

Summary of the invention The present invention overcomes the above disadvantages.

It is an object of the present invention to provide a wear-resistant high pressure diaphragm pump to convey liquids having abrasive or corrosive properties.

It is a further object to provide a diaphragm pump in which the diaphragm is a hose whose cross-section can be varied within a casing to convey the liquid.

A still further object is to provide a diaphragm pump as above for particular use in an airless transport environment.

Brif description of the drawing Other objects and advantages will become apparent from the following description and drawing in which:

FIGURE 1 is an elevation view of the hose diaphragm portion and its casing of the pump, partially in section.

FIGURE 2 is a cross-sectional view taken along line 2-2 of FIGURE 1.

FIGURE 3 is a view similar to that of FIGURE 2 but with the hose diaphragm in expanded operating position.

3,440,970 Patented Apr. 29, 1969 Description of the preferred embodiment Viewing the drawing in greater particularity 6 indicates a cylindrical casing which is pressure resistant. The casing 6 contains the motion generating mechanism for the liquid to be pumped. This mechanism includes a diaphragm 1 in the form of a hose 2 longitudinally oriented within the cylindrical casing 6. The hose 2 is connected at one end to an inlet port 7 by means of a union 8. This hose is made of an elastomeric material, preferably a plastic such as polyamide or polypropylene.

Within the hose are longitudinally stacked and oriented hairpin shaped springs 3 contained within opposed slidingly engageable U-shaped metal strips 5a and 5b. As seen in FIGURE 2, the legs of strip 5a are contained within and in sliding contact with the legs of strip 5b. About the legs of the hairpin shaped springs, adjacent the ends of the legs, are short cylindrically shaped cushions 4, preferably made of rubber, to protect the springs 3 and strips 5a and 512 from excessive wear and noise.

The casing 6 has an inlet and outlet at opposite ends. The inlet 10 permits the liquid to be pumped to enter the casing 6 about the hose diaphragm 1 and then the liquid is discharged through the outlet 11. In the embodiment shown the inlet 10 is at the end of the casing remote from the end containing the cylinder port 7. The outlet 11 is closed to the delivery or atomizing portion of the entire system, and since it is also at the same end of the casing as cylinder port 7 this makes for greater elliciency in the entire unit.

In operation, the liquid to be pumped, is drawn into inlet 10. The hose at this time is relaxed in that the hairpin springs 3 have their legs extended and pushing against the protective strips 5a and 5b to slidingly separate them as far as the hose 2 permits. In this position the hose has a cross-sectional configuration which is oval in shape. The pressurizing medium is then forced through the cylinder port 7 into the hose 2 changing the cross-section of the hose 2 to a circle and simultaneously foreshortening the extent of the strips 5a and 5b. The result is that the area A between the hose 2 and the casing 6 is decreased until the area between the hose and casing is at a minimum as shown by A1 in FIGURE 3. This decrease in area causes the liquid to be pumped, to be forced out of outlet 11. The pressurizing medium pressure is then relieved permitting the hose diaphragm to restore to its shape as shown in FIGURE 2.

The pumping cycle is then repeated.

Having shown and described a preferred embodiment of my invention, it is to be understood that I do not wish to be confined to the precise details of construction set forth herein as it is apparent that changes and variations may be made therein by those skilled in the art, without departing from the spirit of the invention or exceeding the scope of the following claims.

1. A high pressure diaphragm pump comprising:

(A) a tubular shaped diaphragm contained within a cylindrical casing having an inlet and outlet, said diaphragm;

(1) being spring loaded by a plurality of springs to obtain an oval cross-sectional configuration when at rest;

(2) being expansible by a fluid pressuring medium toward an enlarged circular cross-section whereby the cross-sectional area and total volume between said diaphragm and casing is decreased to cause a delivery of liquid from said outlet wherein, said springs 3 are shaped as hairpin shaped pins and are stacked and oriented longitudinally within said diaphragm to urge said diaphragm into said oval configuration.

2. A pump as called for in claim 1 wherein said springs are contained within opposed slidingly engageable U-shaped metal strips contained within said diaphragm, said strips each having two parallel legs, the legs of one of said strips being contained within and in sliding contact with the legs of the other strip, said springs urging said strips apart to give said diaphragm said oval c0nfiguration.

3. A pump as called for in claim 2 wherein said dia phragm is a hose made of an elastomer.

4. A pump as called for in claim 3 wherein said hose is made of a polyamide plastic.

5. A pump as called for in claim 3 wherein said hose is made of a polypropylene plastic.

References Cited UNITED STATES PATENTS 28,758 6/1860 Lapham 230-169 1,405,595 2/ 1922 Kapfeker. 2,735,642 2/1956 Norman 103148 XR 2,849,026 8/1958 Taplin 92l03 3,017,433 4/1963 Cerueny 103-148 XR 3,253,549 5/1966 Vincent et al. 103-148 XR 10 3,335,666 8/1967 Czarnecki.

OTHER REFERENCES Polypropylene, Theodore Kresser, Reinhold Pub. Co., N.Y., 1960, pp.184186.

15 ROBERT M. WALKER, Primary Examiner.

W. J. GOODLIN, Assistant Examiner. 

